3.4.5 Student Book © 2004 Propane Education & Research CouncilPage 1 3.4.5 Maintaining Bulk Plant Pumps, Strainers and Bypass Systems Knowing how to maintain.

3.4.5 Student Book © 2004 Propane Education & Research Council Page 1

3.4.5

Maintaining Bulk Plant Pumps, Strainers and

Bypass Systems

Knowing how to maintain bulk plant pumps, strainers and bypass systems is necessary for a safe and efficient plant operation.

In this module you will learn to identify:

(1) Types of propane pumps

(2) Pump maintenance techniques

(3) The function of strainers and strainer maintenance procedures

(4) Pump protective devices and applicable maintenance techniques


Identifying the Types of Propane Pumps

Two types of pumps used for transferring propane are:

• Regenerative turbine

• Positive displacement

Regenerative Turbine Pumps

Figure 1. Regenerative Turbine Pump

Courtesy of Corken Pump Co.



Regenerative Turbine Pumps





Regenerative Turbine Pumps— Regenerative turbine pumps are used at cylinder docks, dispensing stations, and in other applications that require capacities of up to 25 gallons per minute.





Sliding Vane Pumps

Figure 2. Sliding Vane Pump


At the pump inlet, the distance between the rotor and the pump liner widens and centrifugal force propels the vanes out from the center of the rotor.

As the rotor continues rotating toward the outlet, the oval shape of the liner results in less space between the rotor and the liner wall, acting to compress the liquid and increase its pressure at the pump’s outlet.



Sliding Vane Pumps

Figure 3a. Operation of Sliding Vane Pump

Courtesy of Dover Corp., Blackmer Pump Div.



Sliding Vane Pumps

Figure 3b. Detail Of How Sliding Vanes Are Actuated

Courtesy of Blackmer Pump Div.



Gear Pumps

Figure 4. Gear Pump

Courtesy of Blackmer Pump Div.


Identifying Pump Maintenance Techniques

C om p a n yO & M

P ro c ed u re s

NFPA 58 requires that qualified persons must operate & main-tain bulk plants and industrial installations in accordance with the company’s written operating and maintenance procedures.

Before starting any bulk plant or industrial installation mainten-ance procedure, be sure to review your company’s maintenance procedures and equipment manufacturer’s instructions.

Lubrication Vane and gear-type pump bearings should be lubricated every three (3) months with a light Number 2 Lithium-base type of grease. Apply grease slowly with a hand gun to the grease fittings on each bearing cover until excess grease begins to come from the relief fittings. Do not use a high-pressure grease gun, and stop applying new grease when excess grease appears.



Drive Components

Belt-driven pumps should be examined for proper alignment and condition of the drive belts when lubrication is scheduled.

Shaft coupling-driven pumps should be checked for proper alignment of the couplings and wear of the spacing bushings.

Gear Reduction driven pumps must be checked for proper alignment and wear of their universal joints or couplings as applicable. The gearbox and U-joints should be lubricated according to manufacturer instructions and maintenance recommendations.



At all times during the maintenance of pumps and their drive components, electrical controls should be locked out and tagged according to company procedures.

If the drive belt and pulley guards or coupling guards are removed during inspection or maintenance operations, they must be properly installed and secured before lock out and tag out devices are removed and the equipment is placed back into service.


Strainers and Strainer Maintenance Procedures

Every pump should have a strainer in the inlet piping to protect it against damage from foreign matter in the propane supply.

Figure 5. Propane Strainer

Courtesy of Smith Precision Products


Strainers and Strainer Maintenance Procedures

Selecting and Sizing Strainers

• Most manufacturers recommend that the installed strainer be at least one pipe size larger than the inlet piping.

• They also recommend a strainer with as large a screen area as possible, and to locate it at least ten pipe diameters upstream from the pump inlet, whenever possible.

Strainer Maintenance

• The strainer must be isolated from the rest of the transfer system by closing liquid piping valves upstream and downstream of the strainer.

• Propane trapped in the strainer must be bled off safely.

• The cover must be removed from the bottom of the strainer body or casing and be cleaned using a brass bristle brush and a solvent if necessary.


Other Pump Protective Devices

Flexible Connectors— Pumps are usually connected to the inlet and outlet piping with flexible connectors to avoid serious damage from vibration, expansion and contraction of the piping with heat and cold, and sags or other forces

transmitted to the pump through the plant transfer piping.

Figure 6. Flexible Connector



Hydrostatic Relief Valves — Protection against hydrostatic pressure damage is provided using hydrostatic relief valves.

Figure 7. Hydrostatic Relief Valve

Courtesy of Sherwood Corp



Selecting and Maintaining Hydrostatic Relief Valves —Hydrostatic relief valves must be designed to open at a pressure of not less than 400 psig and not more than 500 psig when selecting new or replacement valves.

Figure 8. Hydrostatic Relief Valves With Rain Caps

Hydrostatic relief valves should be fitted with rain caps to prevent moisture and debris from accumulating inside the valve.



Pump Internal Relief Valves

Figure 9. Internal Relief Valve



Manual and Automatic Bypass Circuits

Figure 9. Internal Relief Valve



Manual and Automatic Bypass Circuits

Figure 11. Automatic Bypass Valve



Maintaining Automatic Bypass Valves

The bypass valve should be set at least 15 to 20 psi below the pump’s internal relief valve setting. Qualified personnel using properly selected liquid-filled pressure gauges (rated for 0-400 psig service) can adjust the valve’s opening setting if the automatic bypass is not opening at the proper pressure to protect the pump.

To determine the automatic bypass opening setting or to adjust the setting, follow your company’s written maintenance procedures and equipment manufacturer instructions.

3.4.5 Student Book © 2004 Propane Education & Research Council Pages 18 - 20

Time to See If You Got the Key Points of This Module…

• Complete the Review on pages 18 & 19.

• See if you are ready for the Certification Exam by checking off the performance criteria on page 20.

3.4.5 Student Book © 2004 Propane Education & Research CouncilPage 1 3.4.5 Maintaining Bulk Plant Pumps, Strainers and Bypass Systems Knowing how to maintain.

Documents

types of pumps

pump liner

pumps outlet

vane pumps figure

pump inlet

bulk plant pumps

student book

pump protective devices